In general, a semiconductor device includes scribe lines and bonding pads. The former is required for dividing a wafer into chips by dicing, and the latter is required for wire bonding. When manufacturing such a semiconductor device, it is a common method to remove a passivation film (for example, silicon oxide film, silicon nitride film, or other films) provided on the scribe lines and the bonding pads before dividing a wafer into chips. FIG. 3(a) and FIG. 3(b) illustrate an example of such a method.
First, as shown in FIG. 3(a), a bonding pad 12 and a scribe line 13 are provided on a substrate 11, and a passivation film 14 is provided so as to cover the substrate thus provided with the bonding pad 12 and the scribe line 13. Then, a photoresist 15 is applied to the passivation film 14 so as to form a photoresist pattern by exposure. The photoresist pattern is formed in such a manner that openings are formed above the bonding pad 12 and the scribe line 13.
Next, as shown in FIG. 3(b), the photoresist 15 having such a predetermined pattern thus prepared is used as a mask so as to remove the passivation film 14 provided on the bonding pad 12 and the scribe line 13. For this purpose, the plasma etching method or other methods may be adopted. Thereafter, the photoresist 15 is removed.
A photoresist pattern adopted in a conventional semiconductor device has a problem in that if a passivation film has a thickness in an order of several .mu.m, when exposing and developing a photoresist, developer and a resist residue remain on the photoresist pattern. This adversely affects the etching of the passivation film such that abnormal etching is caused and an etching residue is generated. Note that, when adopting a thin passivation film having a thickness in an order of hundreds of nm, the above-mentioned problems are not caused.
FIG. 4(a) shows respective portions of the bonding pad 12 and the scribe line 13 of a conventional semiconductor device. FIG. 4(a) also shows a photoresist pattern (portions enclosed by the alternate long and two short dashes) which is formed when portions of the passivation film 14 covering the bonding pad 12 and the scribe line 13 are selectively removed. Namely, the photoresist pattern is formed such that opening sections 15a and 15b of the photoresist 15 are provided respectively above the bonding pad 12 and the scribe line 13.
FIG. 4(b) is a cross sectional view taken along a line B--B of FIG. 4(a). In a conventional arrangement, as shown in FIG. 4(b), a resist residue 16 remains at the bottom of the opening section 15a above the bonding pad 12.
FIG. 4(c) is a cross sectional view showing the semiconductor device from which the photoresist 15 has been removed. As shown in FIG. 4(c), a removing solution or an etching residue 17 remain in the opening section 14a corresponding to the bonding pad 12. This causes a quality deterioration such as corrosion of a bonding pad and breakage of wire bonding.